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3.3 Methods
3.3.3 Data collection- Presence across the landscape
We identified Spotted Thick-knee locations in Pietermaritzburg using two methods of approach during 2019 and 2020. Our first approach consisted of pilot observations carried out between 1 April 2019 and 30 June 2019 in public spaces and other accessible spaces across the city landscape at areas where the study species could have potentially been found or was sighted before the study commenced. The potential locations, environments and conditions for the presence of individuals/groups/populations of the study species were based on current knowledge in existing literature and before-study observations of already identified locations of individuals/groups of the study species. The potential locations were first identified using
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Google Earth (Version 7.3.2) followed by actively surveying those identified areas to ground truth them and visited any other areas of possible Spotted Thick-knee occurrence whilst carrying out field surveys. We conducted these surveys during the day between 08h00 and 17h00 when Spotted Thick-knees were least active in terms of movement. We did this until all publicly accessible areas of Pietermaritzburg were surveyed. The geographic locations of identified Spotted Thick-knees were recorded using a Global Positioning System (GPS) and tabulated in a Microsoft Excel Spreadsheet. From this approach, 26 site locations were found by the start of the study field sampling on 18 July 2019.
Our second approach utilised citizen science through public participation in the form of a newspaper article request for any geographic locations and/or information on Spotted Thick- knees' sightings by the public (Supplementary Material S3.1). The article was distributed to the public in the first week of June 2019, in newspapers delivered throughout Pietermaritzburg and surrounding areas, often for free. There was a total of 178 respondents to the article, but three respondents gave sighting information for locations outside the study area and therefore excluded from data collection and data analyses. Some participants gave multiple locations for Spotted Thick-knee sightings and there were a few data points that were duplicated, in terms of the general area where the Spotted Thick-knee were sighted. Through this approach, we identified 61 geographic locations of potential Spotted Thick-knee presence in the study area, but after ground-truthing locations and vetting reports of sightings from respondents, we excluded 20 geographic locations from further data collection and analyses. We excluded these locations in the study because they were locations where Spotted Thick-knees had not been seen for more than 10 years; urban development had taken place at a large scale, and there was no natural landscape within 75 m radius of the site GPS location; private properties that denied access when asked for permission; and sites with a false report resulting from the respondent incorrectly identifying the bird species they sighted as a Spotted Thick-knee or the eggs of
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other ground-nesting species (e.g., Crowned Lapwing (Vanellus coronatus)) as Spotted Thick- knee eggs.
We combined the 26 locations obtained using the first approach with 41 locations from the second approach giving a total of 52 locations because some sites were found through both approaches resulting in duplications. We visited 47 sites from July 2019 to December 2020;
while 1 site was visited from September 2019 to December 2020; 2 sites were visited from October 2019 to December 2020; 1 site from November 2019 to December 2020; and 1 site from January 2020 to December 2020. These five sites were not visited from the start because respondents contacted the study investigator after the commencement of field data collection.
No field data collection took place during the months of March 2020, April 2020 and May 2020 because of South Africa’s National Lockdown Regulations in response to the COVID-19 global pandemic.
We visited sites at least once month, but if the study species was not present during the first monthly visit, the site was revisited for a maximum of four further visits on temporally randomised days to get a recording for that specific month. If at least one Spotted Thick-knee was observed during a visit, the site location was recorded as ‘present’ for that month and recorded as ‘not present’ if there was no observed presence of the study species after five monthly visits. The duration spent at each site was a maximum of 15 min. If the study species was not found at the site at the end of the 15 min., it was recorded as ‘not present’ for that respective visit. The study species had mobility and was not expected to be at the exact same place as the original sighting. Therefore, a maximum radius distance of 75 m from the original GPS location (as the centre reference point) where the species was first observed, was used to determine whether the study species was still present in that relative location. 100 m was the maximum distance the observer could clearly see and accurately identify the study species.
However, in some cases, it was impossible to clearly see the surroundings at 100 m for a full
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360̊ view because of obstruction of sight by obstacles such as buildings, walls and trees etc. It was unavoidable that for some sites on private properties, access was limited to an area less than 75 m radius from the original GPS location. Sites within the same suburb or in relatively close distance were visited on the same day to reduce the possibility that the same individuals were seen at different locations within the assumed movement range of the study species.